Islamic Lunar Calendar

Prophet Muhammad's hijra ("flight" or "migration") from Mecca to Medina in 622 AD marks the beginning of the Islamic lunar calendar. This is why Muslim dates have the suffix AH (After Hijra). The Islamic lunar year (354 or 355 days) is between 10 and 12 days shorter than the "Western" or "Christian" Gregorian solar year (365 or 366 days).[1]

Muhammad's child bride, Aisha, was 9 years-old at the time of her consummation according to the Islamic calender. Therefore it is quite possible that she was aged only 8 years at the time of her consummation according to the Gregorian calendar, which is internationally the most widely accepted and used civil calendar.[2][3][4]